Dialog System

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The default CEGUI implementation stores the currently specified values of the widgets such that closing and then reopening a window will redisplay those values. Presented here is a different approach, to allow values to be saved or cancelled.

Explanation

The DemoSample class is the "main" application. It initializes CEGUI and loads a simple layout. It then initialises instances of the SimpleWindow and the SimpleDialog classes. These contain the specific code to handle the behavior of the Simple Window and the Simple Dialog. In turn they rely on the behaviors define within the DialogSystem class to activate higher level features.

The DialogSystem class implements the behavior of the 'Ok', 'Cancel', and 'Apply' buttons that we've become accustomed to in the world of Windows. The DialogSystem::DialogSystemEvents enumaration defines the high level events supported by the DialogSystem class:

 open: display the window and its data
 ok: save the data and close the window
 cancel: close the window without saving the data
 escape: close the window without saving the data
 apply: save the data without closing the window
 modified: enable the 'apply' button

These high level events accomplish their jobs through the use of four basic actions:

 doOpen(): display the window
 doLoad(): copy the value of variables into their associated widgets
 doSave(): copy the value of the widgets into their associated variables
 doClose(): hide the window

The SimpleWindow class will manage everything that has to do with the Simple Window. The initWindow() function initialises the DialogSystem by specifying the handle of the window/dialog (the name specified within the layout file) and whether it should initially be visible or not. Then it instructs the DialogSystem to handle four events as well as which action to initiate in response to these events: 1) Pressing the "Toolbar_btnSimpleWindow" button opens the SimpleWindow. 2) Pressing the "SimpleWindow_btnClose" button performs an 'Ok', saving the data and closing the window. 3) Clicking on the 'X' button closes the dialog without saving any modifications (cancel). 4) Pressing the 'escape' key closes the dialog without saving any modifications (cancel).

The SimpleWindow class then overrides the doLoad() virtual function to place the contents of a variable (dataString) into its associated Editbox. It also overrides the doSave() virtual function to place the contents of the Editbox back into the variable.

The SimpleDialog class replicates many of what the SimpleWindow performed. The first difference is that it specifies the handle of a parent window. This signals the DialogSystem class that when the Simple Dialog is opened it should disable its parent, making the Simple Dialog modal; inputs to the parent are blocked while this dialog is opened.

The second difference is the addition of an apply button. This apply button requires that two events be specified. The event of clicking on the apply button "SimpleDialog_btnApply" is bound to the high level event of DialogSystem::apply, which will call upon doSave() to move the widget data into the variables. Text changes within the edit box "SimpleDialog_edtValue" are also bound to the high level event of DialogSystem::modified, which will enable the apply button whenever the contents of the edit box are modified. If there were additional widgets within the window then their 'modified' events would also need to be specified.

CEGUI has more widgets than an Editbox. These can easily be incorporated within the logic presented here.

Please post comments or questions on the message board thread for the Dialog System

DialogSystemDemo.h

#ifndef _DialogSystemDemo_h_
#define _DialogSystemDemo_h_

#include "CEGuiSample.h"
#include "CEGUI.h"
#include "DemoUtils.h"
#include "DialogSystem.h"

class SimpleWindow : public DialogSystem
{
public:
	void initWindow()
	{
		// Initialise the window
		using namespace CEGUI;

		// Initialise the windowing system
		DialogSystem::initialise("winSimpleWindow",	// The handle of this window
					false);			// Initially invisible
								// A modeless window does not have a parent

		// Subscribe to widget events
		// Note that the "close" button is set to behave as an "ok" button
		DialogSystem::bindEvent( "Toolbar_btnSimpleWindow",	PushButton::EventClicked, DialogSystem::open);
		DialogSystem::bindEvent( "SimpleWindow_btnClose",	PushButton::EventClicked, DialogSystem::ok);

		// Subscribe to window events
		DialogSystem::bindEvent("winSimpleWindow", FrameWindow::EventCloseClicked,	DialogSystem::cancel); // The 'X' button was clicked
		DialogSystem::bindEvent("winSimpleWindow", FrameWindow::EventKeyDown,		DialogSystem::escape); // The 'escape' key was pressed
	}
protected:
	bool doLoad()
	{
		// Handle the load action by placing data into widgets
		CEGUI::WindowManager::getSingleton().getWindow("SimpleWindow_edtValue")->setText(dataString);
		return DialogSystem::doLoad(); 
	}
	bool doSave()
	{
		// Handle the save action by moving widget data into variables
		dataString = CEGUI::WindowManager::getSingleton().getWindow("SimpleWindow_edtValue")->getText();
		return DialogSystem::doSave(); 
	}
private:
	CEGUI::String dataString; // Variable associated with the Editbox
};

//////////////////////////////////////////////

class SimpleDialog : public DialogSystem
{
public:
	void initWindow()
	{
		// Initialise the dialog
		using namespace CEGUI;
		WindowManager& winMgr = WindowManager::getSingleton();

		// Initialise the windowing system
		DialogSystem::initialise("dlgSimpleDialog",	// The handle of this window
					false,			// Initially invisible
						"winToolbar");	// The handle of its parent, making it a modal dialog

		// Subscribe to widget events
		DialogSystem::bindEvent( "Toolbar_btnSimpleDialog",	PushButton::EventClicked,	DialogSystem::open);
		DialogSystem::bindEvent( "SimpleDialog_btnOk",		PushButton::EventClicked,	DialogSystem::ok);
		DialogSystem::bindEvent( "SimpleDialog_btnCancel",	PushButton::EventClicked,	DialogSystem::cancel);
		DialogSystem::bindEvent( "SimpleDialog_btnApply",	PushButton::EventClicked,	DialogSystem::apply);

		// These events trigger a 'modified' event, activating the 'apply' button
		DialogSystem::bindEvent( "SimpleDialog_edtValue",	Editbox::EventTextChanged,	DialogSystem::modified);

		// Subscribe to window events
		// Pressing the 'X' button will behave as a cancel
		DialogSystem::bindEvent( "dlgSimpleDialog", FrameWindow::EventCloseClicked,	DialogSystem::cancel); // The 'X' button was clicked
		DialogSystem::bindEvent( "dlgSimpleDialog", FrameWindow::EventKeyDown,		DialogSystem::escape); // The 'escape' key was pressed
	}
protected:
	bool doLoad()
	{
		// Handle the load action by placing data into widgets
		CEGUI::WindowManager::getSingleton().getWindow("SimpleDialog_edtValue")->setText(dataString);
		return DialogSystem::doLoad(); 
	}
	bool doSave()
	{
		// Handle the save action by moving widget data into variables
		dataString = CEGUI::WindowManager::getSingleton().getWindow("SimpleDialog_edtValue")->getText();
		return DialogSystem::doSave(); 
	}
private:
	CEGUI::String dataString;
};

//////////////////////////////////////////

class DemoSample : public CEGuiSample
{
public:
    bool initialiseSample()
	{
		using namespace CEGUI;
		try
		{
			// Retrieve the window manager
			WindowManager& winMgr = WindowManager::getSingleton();

			// Load the TaharezLook scheme and set up the default mouse cursor and font
			SchemeManager::getSingleton().loadScheme("TaharezLook.scheme");
			System::getSingleton().setDefaultMouseCursor("TaharezLook", "MouseArrow");
			if(!FontManager::getSingleton().isFontPresent("Commonwealth-10"))
				FontManager::getSingleton().createFont("Commonwealth-10.font");

			// Set the GUI Sheet
			Window* sheet = winMgr.createWindow("DefaultWindow", "root_wnd");
			System::getSingleton().setGUISheet(sheet);

			// Load a layout
			Window* guiLayout = winMgr.loadWindowLayout("DialogSystem.layout");
			sheet->addChildWindow(guiLayout);


			// Initialise the Simple Window and the Simple Dialog
			simpleWindow.initWindow();
			simpleDialog.initWindow();
		}
		catch(Exception &e)
		{
			ErrorMessage(e.getMessage().c_str(), "Error initializing the demo");
		}

		return true;
	}

    void cleanupSample(void)
	{
	}
private:
	SimpleWindow simpleWindow;
	SimpleDialog simpleDialog;
};

#endif // _DialogSystemDemo_h_

DialogSystem.h

#ifndef _DialogSystem_h_
#define _DialogSystem_h_

#include "CEGUI.h"
#include "vector"

class DialogSystem
{
public:
	DialogSystem();
	enum DialogSystemEvents { open, ok, cancel, escape, apply, modified };
	bool isModified(); // Return whether data within the window is modified

	// Actions
	virtual bool doOpen(); // Open the window
	virtual bool doLoad(); // Assign the data into the widgets
	virtual bool doSave(); // Assign the widgets into the data
	virtual bool doClose(); // Close the window
	void initialise(const CEGUI::String& window, bool visible, const CEGUI::String& parent = ""); // Initialise the window system
	void bindEvent(const CEGUI::String& widget, const CEGUI::String& event, DialogSystem::DialogSystemEvents action); // Subscribe to window events
private:
	// Events
	bool onOpen(const CEGUI::EventArgs& e); // Open the window
	bool onOk(const CEGUI::EventArgs& e); // Save the data and close the window
	bool onCancel(const CEGUI::EventArgs& e); // Close the window
	bool onEscape(const CEGUI::EventArgs& e); // Close the window
	bool onApply(const CEGUI::EventArgs& e); // Save the data
	bool onModified(const CEGUI::EventArgs& e); // A widget in the window has been modified

	CEGUI::String m_parent; // Handle to the parent
	CEGUI::String m_window; // Handle to the window
	CEGUI::String m_apply;  // Handle of the apply button
	bool m_modal; // Whether the window is modal
};

#endif // _DialogSystem_h_

DialogSystem.cpp

#include "DialogSystem.h"
#include "assert.h"

DialogSystem::DialogSystem()
{
	m_modal  = false;
}

bool DialogSystem::isModified()
{
	// Return whether data within the window is modified
	assert(!m_apply.empty() && "The isModified() function requires that you specify an \"Apply\" button");
	return !CEGUI::WindowManager::getSingleton().getWindow(m_apply)->isDisabled();
}

bool DialogSystem::doOpen()
{
	// Open the window
	assert(!m_window.empty() && "You have forgotten to call initialise()");
	if(m_modal)
	{
		// Displaying a modal window disables its parent
		assert(!m_parent.empty() && "The value of m_modal or m_parent has become corrupted");
		CEGUI::WindowManager::getSingleton().getWindow(m_parent)->setEnabled(false);
	}

	// Display the window
	CEGUI::WindowManager::getSingleton().getWindow(m_window)->setVisible(true);

	// Load the data into the widgets
	return doLoad();
}

bool DialogSystem::doLoad()
{
	// Populate the window widgets with data
	// Note that this can also be used to simulate an undo for every widget
	// present in the window

	// Disable the apply button since there are no modifications
	if(!m_apply.empty())
		CEGUI::WindowManager::getSingleton().getWindow(m_apply)->setEnabled(false);
	return true;
}

bool DialogSystem::doSave()
{
	// Update the data with the inputs from the widgets

	// Disable the apply button since there are no modifications
	if(!m_apply.empty())
		CEGUI::WindowManager::getSingleton().getWindow(m_apply)->setEnabled(false);

	return true;
}

bool DialogSystem::doClose()
{
	// Close the window
	assert(!m_window.empty() && "You have forgotten to call initialise()");

	if(m_modal)
	{
		// Closing a modal window enables its parent
		assert(!m_parent.empty() && "The value of m_modal or m_parent has become corrupted");
		CEGUI::WindowManager::getSingleton().getWindow(m_parent)->setEnabled(true);
	}

	CEGUI::WindowManager::getSingleton().getWindow(m_window)->setVisible(false);
	return true;
}

void DialogSystem::initialise(const CEGUI::String& window, bool visible, const CEGUI::String& parent)
{
	// Initialise the window system
	// Specifying a parent makes this window modal
	m_window = window;
	CEGUI::WindowManager::getSingleton().getWindow(m_window)->setVisible(visible);
	m_parent = parent;
	m_modal  = !m_parent.empty();
}


void DialogSystem::bindEvent(const CEGUI::String& widget, const CEGUI::String& widgetEvent, DialogSystemEvents action)
{
	// Subscribe to events
	CEGUI::Window* widgetHandle = CEGUI::WindowManager::getSingleton().getWindow(widget);
	switch(action)
	{
	case open:
		widgetHandle->subscribeEvent(widgetEvent, CEGUI::Event::Subscriber(&DialogSystem::onOpen, this));
		break;
	case ok:
		widgetHandle->subscribeEvent(widgetEvent, CEGUI::Event::Subscriber(&DialogSystem::onOk, this));
		break;
	case cancel:
		widgetHandle->subscribeEvent(widgetEvent, CEGUI::Event::Subscriber(&DialogSystem::onCancel, this));
		break;
	case escape:
		widgetHandle->subscribeEvent(widgetEvent, CEGUI::Event::Subscriber(&DialogSystem::onEscape, this));
		break;
	case apply:
		widgetHandle->subscribeEvent(widgetEvent, CEGUI::Event::Subscriber(&DialogSystem::onApply, this));
		m_apply = widget;
		break;
	case modified:
		if(!m_apply.empty())
			widgetHandle->subscribeEvent(widgetEvent, CEGUI::Event::Subscriber(&DialogSystem::onModified, this));
		break;
	}
}

bool DialogSystem::onOpen(const CEGUI::EventArgs& e)
{
	// Open the window
	return doOpen();
}

bool DialogSystem::onOk(const CEGUI::EventArgs& e)
{
	// The 'ok' button was pressed
	// Respond by saving the data and closing the window
	return doSave() && doClose();
}

bool DialogSystem::onCancel(const CEGUI::EventArgs& e)
{
	// The 'cancel' button was pressed
	// Respond by closing the window without saving the data
	return doClose();
}

bool DialogSystem::onEscape(const CEGUI::EventArgs& e)
{
	// The 'escape' key was pressed
	// Respond by closing the dialog without saving the data
	// Note that Win32AppHelper::doDirectInputEvents() intercepts this key
	// This means that the escape key will NOT reach here
    const CEGUI::KeyEventArgs& keyArgs = static_cast<const CEGUI::KeyEventArgs&>(e);
	if(keyArgs.scancode == CEGUI::Key::Escape)
	{
		return doClose();
	}
	else
		return false;
}

bool DialogSystem::onApply(const CEGUI::EventArgs& e)
{
	// The 'apply' button was pressed
	// Respond by saving the data without closing the window
	return doSave();
}

bool DialogSystem::onModified(const CEGUI::EventArgs& e)
{
	// A widget within the window was modified
	// Respond by enabling the 'apply' button
	CEGUI::WindowManager::getSingleton().getWindow(m_apply)->setEnabled(true);
	return true;
}


DialogSystem.layout

<?xml version="1.0" encoding="UTF-8"?>

<GUILayout >
    <Window Type="DefaultWindow" Name="Root" >
        <Property Name="InheritsAlpha" Value="False" />
        <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
        <Property Name="UnifiedAreaRect" Value="{{0,0},{0,0},{1,0},{1,0}}" />
        <Window Type="TaharezLook/FrameWindow" Name="winToolbar" >
            <Property Name="Text" Value="Toolbar" />
            <Property Name="AlwaysOnTop" Value="True" />
            <Property Name="TitlebarFont" Value="Commonwealth-10" />
            <Property Name="CaptionColour" Value="00FFFFFF" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="TitlebarEnabled" Value="False" />
            <Property Name="UnifiedAreaRect" Value="{{0.24875,0},{0.010001,0},{0.568749,0},{0.081667,0}}" />
            <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseTarget" />
            <Property Name="CloseButtonEnabled" Value="False" />
            <Window Type="TaharezLook/Button" Name="Toolbar_btnSimpleWindow" >
                <Property Name="Text" Value="Simple Window" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.065103,0},{0.227595,0},{0.475554,0},{0.686899,0}}" />
                <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseArrow" />
            </Window>
            <Window Type="TaharezLook/Button" Name="Toolbar_btnSimpleDialog" >
                <Property Name="Text" Value="Simple Dialog" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.538253,0},{0.227595,0},{0.948703,0},{0.686899,0}}" />
                <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseArrow" />
            </Window>
        </Window>
        <Window Type="TaharezLook/FrameWindow" Name="winSimpleWindow" >
            <Property Name="Text" Value="Simple Window" />
            <Property Name="TitlebarFont" Value="Commonwealth-10" />
            <Property Name="CaptionColour" Value="00FFFFFF" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="TitlebarEnabled" Value="True" />
            <Property Name="UnifiedAreaRect" Value="{{0.005,0},{0.168333,0},{0.42,0},{0.511666,0}}" />
            <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseTarget" />
            <Window Type="TaharezLook/Button" Name="SimpleWindow_btnClose" >
                <Property Name="Text" Value="Close" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.688554,0},{0.804855,0},{0.938554,0},{0.943204,0}}" />
                <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseArrow" />
            </Window>
            <Window Type="TaharezLook/StaticText" Name="SimpleWindow_lblValue" >
                <Property Name="Font" Value="Commonwealth-10" />
                <Property Name="Text" Value="Value:" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.455591,0},{0.430746,0},{0.606068,0},{0.569095,0}}" />
            </Window>
            <Window Type="TaharezLook/Editbox" Name="SimpleWindow_edtValue" >
                <Property Name="Font" Value="Commonwealth-10" />
                <Property Name="MaxTextLength" Value="1073741823" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.618241,0},{0.430746,0},{0.970525,0},{0.569095,0}}" />
            </Window>
        </Window>
        <Window Type="TaharezLook/FrameWindow" Name="dlgSimpleDialog" >
            <Property Name="Text" Value="Simple Dialog" />
            <Property Name="TitlebarFont" Value="Commonwealth-10" />
            <Property Name="CaptionColour" Value="00FFFFFF" />
            <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
            <Property Name="TitlebarEnabled" Value="True" />
            <Property Name="UnifiedAreaRect" Value="{{0.43625,0},{0.165,0},{0.916249,0},{0.508333,0}}" />
            <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseTarget" />
            <Window Type="TaharezLook/Button" Name="SimpleDialog_btnOk" >
                <Property Name="Text" Value="Ok" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.173754,0},{0.804855,0},{0.423754,0},{0.943204,0}}" />
                <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseArrow" />
            </Window>
            <Window Type="TaharezLook/Button" Name="SimpleDialog_btnCancel" >
                <Property Name="Text" Value="Cancel" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.451828,0},{0.804855,0},{0.701828,0},{0.943204,0}}" />
                <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseArrow" />
            </Window>
            <Window Type="TaharezLook/Button" Name="SimpleDialog_btnApply" >
                <Property Name="Text" Value="Apply" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.73123,0},{0.804855,0},{0.98123,0},{0.943204,0}}" />
                <Property Name="MouseCursorImage" Value="set:TaharezLook image:MouseArrow" />
            </Window>
            <Window Type="TaharezLook/Editbox" Name="SimpleDialog_edtValue" >
                <Property Name="Font" Value="Commonwealth-10" />
                <Property Name="MaxTextLength" Value="1073741823" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.626093,0},{0.418446,0},{0.971449,0},{0.556795,0}}" />
            </Window>
            <Window Type="TaharezLook/StaticText" Name="SimpleDialog_lblValue" >
                <Property Name="Text" Value="Value:" />
                <Property Name="UnifiedMaxSize" Value="{{1,0},{1,0}}" />
                <Property Name="UnifiedAreaRect" Value="{{0.482291,0},{0.418446,0},{0.617709,0},{0.556795,0}}" />
            </Window>
        </Window>
    </Window>
</GUILayout>

main.cpp

#if defined( __WIN32__ ) || defined( _WIN32 )
	#define WIN32_LEAN_AND_MEAN
	#define NOMINMAX
	#include "windows.h"
#endif

#include "DialogSystemDemo.h"


#if defined( __WIN32__ ) || defined( _WIN32 )
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine,int nCmdShow)
#else
int main(int argc, char *argv[])
#endif
{
    DemoSample app;
    return app.run();
}